In the course of taking certain X-rays, as is in the case of mammograms, it is necessary for the operator to record the angle at which the X-ray is taken in order that subsequent X-rays of the same patient may be taken at the same angle. The unique physical features of each individual are different, and as a result the most desirable angle at which mammograms are taken are different from individual to individual. In order to study changes in breast material of a patient over a period of time, each mammogram of a given patient must all be taken at the same angle, and therefore the angle at which each mammogram is taken must be recorded.
Mammogram machines consist of an X-ray gun which projects a ray through a paddle and a film holder assembly between which the patient's breast is positioned, and the photographic plate is positioned below the paddle. The X-ray gun and the paddle and the film holding assembly are held in fixed relationship to each other on what is generally referred to as a "C-arm", and the C-arm, including the gun and connected paddle and film holder assembly, is rotatable around a horizontal axis such that mammograms of a breast may be taken at any angle.
Presently, mammogram machines are provided with an angular scale surrounding the horizontal shaft in which the C-arm is mounted. The operator visually reads the angle of the C-arm on each mammographic exposure and manually notes the angle on the records for each film. A portion of tape, or other material, upon which the angle of the C-arm can be written, may also be attached to each film such that the angle of the C-arm is readily ascertainable by examining the film itself.
When several mammograms are taken at a plurality of angles, a technologist may inadvertently interchange the records for mammographic plates and thereby create confusion with the records of a patient. Furthermore, a technologist may inadvertently misread the angle at which a C-arm is positioned during the course of a mammogram, or position the C-arm at an angle different from that intended by the technologist. In any of these cases, the resulting mammograms will be confusing and inhibit the ability of a radiologist to properly diagnose a patient's condition.
The problems which occur with the present method would be overcome if the angle at which a mammogram machine or any other X-ray machine, is operated would be automatically projected upon the photographic plate at the time of its exposure to X-rays.